In the field of conventional mobile phones, most antennas of the mobile phones are externally mounted, i.e., the antennas extend to the outside of the mobile phone. Such an arrangement has a defect of imperfect appearance, and at the same time, occupies too much space. Then, built-in antennas are adopted in the field of mobile phones, that is, the antennas are placed inside an outer cover of the mobile phone, thereby solving the problem of appearance.
Currently, due to the use of a metal middle frame in the mobile phone, most terminal manufacturers directly set a middle frame of a mobile phone as an antenna of the mobile phone. However, an iron housing of a USB connector that passes through the metal middle frame would severely interfere with a radio-frequency signal of the antenna of the mobile phone.